https://gcc.gnu.org/g:01be7efe45f357600a722f9664264459efa201f5
commit 01be7efe45f357600a722f9664264459efa201f5 Author: Mikael Morin <[email protected]> Date: Thu Aug 20 20:43:23 2026 +0200 fortran: array descriptor: Don't set the span in the scalar case [PR122521] Fortran-tested on aarch64-unknown-linux-gnu. OK for mainline? -- >8 -- The span in an array descriptor is a multiplier of the stride representing the address difference between two consecutive array elements. For scalar descriptors, there is a single element, so it can't be used in any useful way. This patch removes the initialization of the span of descriptors in the scalar case. One tweak is required to avoid regressing. In the library implementation of the ASSOCIATED intrinsic, the two descriptors are checked to have the same span, assuming the span to be always set. Make that check conditional on the rank being non-zero. The testcase coarry_collectives_18.f90, which counts the number of array descriptor references in the generated tree dump, needs to be updated as a result of this change. There are two descriptor initializations, and for each of them the change causes a copy from the elem_len field to the span to be removed. So the count is decreased by 4. PR fortran/122521 gcc/fortran/ChangeLog: * trans-descriptor.cc (gfc_set_descriptor_from_scalar): Remove descriptor span initialization. libgfortran/ChangeLog: * intrinsics/associated.c (associated): Only compare spans if the rank is non-zero. gcc/testsuite/ChangeLog: * gfortran.dg/coarray_collectives_18.f90: Update pattern count. Diff: --- gcc/fortran/trans-descriptor.cc | 2 -- gcc/testsuite/gfortran.dg/coarray_collectives_18.f90 | 2 +- libgfortran/intrinsics/associated.c | 5 +++-- 3 files changed, 4 insertions(+), 5 deletions(-) diff --git a/gcc/fortran/trans-descriptor.cc b/gcc/fortran/trans-descriptor.cc index 3f86be584428..23321b5b48cb 100644 --- a/gcc/fortran/trans-descriptor.cc +++ b/gcc/fortran/trans-descriptor.cc @@ -907,8 +907,6 @@ gfc_set_descriptor_from_scalar (stmtblock_t *block, tree descr, tree scalar) gfc_conv_descriptor_dtype_set (block, descr, gfc_get_dtype_rank_type (0, etype)); gfc_conv_descriptor_data_set (block, descr, scalar); - gfc_conv_descriptor_span_set (block, descr, - gfc_conv_descriptor_elem_len_get (descr)); } diff --git a/gcc/testsuite/gfortran.dg/coarray_collectives_18.f90 b/gcc/testsuite/gfortran.dg/coarray_collectives_18.f90 index c83899de0e5b..5636a89e94a9 100644 --- a/gcc/testsuite/gfortran.dg/coarray_collectives_18.f90 +++ b/gcc/testsuite/gfortran.dg/coarray_collectives_18.f90 @@ -33,5 +33,5 @@ end program ! This lead to access to non exsitant memory in opencoarrays. ! In single image mode just checking for reduced number of ! descriptors is possible, i.e., execute always works. -! { dg-final { scan-tree-dump-times "desc\\.\[0-9\]+" 12 "original" } } +! { dg-final { scan-tree-dump-times "desc\\.\[0-9\]+" 8 "original" } } diff --git a/libgfortran/intrinsics/associated.c b/libgfortran/intrinsics/associated.c index fecc1b3a2832..b597b862d031 100644 --- a/libgfortran/intrinsics/associated.c +++ b/libgfortran/intrinsics/associated.c @@ -37,13 +37,14 @@ associated (const gfc_array_void *pointer, const gfc_array_void *target) return 0; if (GFC_DESCRIPTOR_DATA (pointer) != GFC_DESCRIPTOR_DATA (target)) return 0; - if (GFC_DESCRIPTOR_SPAN (pointer) != GFC_DESCRIPTOR_SPAN (target)) - return 0; if (GFC_DESCRIPTOR_DTYPE (pointer).type != GFC_DESCRIPTOR_DTYPE (target).type) return 0; rank = GFC_DESCRIPTOR_RANK (pointer); if (rank != GFC_DESCRIPTOR_RANK (target)) return 0; + if (rank != 0 + && GFC_DESCRIPTOR_SPAN (pointer) != GFC_DESCRIPTOR_SPAN (target)) + return 0; for (n = 0; n < rank; n++) { long extent;
